What it is and what it carries
The Siemens SENTRON 3VA2450-5MN32-0AG0 is a 3-pole molded case circuit breaker (MCCB) rated for 500 A continuous current at 40 °C, with an ETU350M electronic trip unit and integrated phase failure detection. It is a current-production part within the SENTRON family, designed for motor protection duty in industrial power distribution. The ETU350M trip unit provides adjustable overload and short-circuit protection curves, plus phase-failure detection — meaning it will trip on a lost phase before a motor single-phases and burns out. That makes it a fit for pump, fan, and compressor circuits where phase loss is a known failure mode.
Breaking capacity — what it clears at your voltage
At 240 V it interrupts 187 kA; at 415 V and 440 V it holds 121 kA; at 500 V it drops to 75.6 kA; at 690 V it still clears 17 kA. These are the maximum fault currents the breaker can safely interrupt at each voltage level — critical for sizing the upstream transformer and verifying the available fault current at the panel doesn't exceed the breaker's rating.
Thermal derating and panel fit
Full 500 A rating holds through 50 °C ambient; at 55 °C it derates to 495 A, at 60 °C to 490 A, at 65 °C to 485 A, and at 70 °C to 480 A. Operating range is -25 °C to +70 °C, storage from -40 °C to +80 °C. The 138 mm width × 248 mm height × 110 mm depth footprint fits standard MCCB panel cutouts — no special adapter plate needed for a typical 3-pole 500 A frame.
Auxiliary contacts and trip alarm
Comes with one auxiliary switch and one trip alarm switch (HP version), plus a visible trip indicator on the front. The auxiliary contacts let a PLC or SCADA system read the breaker's position and fault status — useful for condition monitoring in wind turbine pitch cabinets or compressor skids where no up-tower swap is acceptable.